This invention relates generally to the electrical connector art and, more particularly, to a contact retention clip and a method of installing the same in the insulator of an electrical connector.
U.S. Pat. No. 4,114,976 to Selvin et al., assigned to the assignee of the present application, discloses a contact retention clip having outwardly extending barbs thereon. After the clip is inserted into a contact cavity in a connector insulator, a heated probe is inserted into the clip to soften the wall of the insulator surrounding the clip, and to expand the clip causing the barbs thereon to become embedded into the softened wall. The embedded barbs enhance the retention of the clip in the connector cavity.
As stated in the aforementioned Selvin et al. patent, a particular material which may be utilized as the insulator for the connector is a polysulfone type polymer. A preferred polymer of this type is a polyethersulfone. Problems are occasionally encountered in the use of such material as the insulator of an electrical connector in that micro cracks may occur in the insulator due to stresses during molding or during post baking of the insulator. When the contact cavities in the insulator are closely spaced, the thickness of the plastic will between the cavities may be only 9 to 11 mils. With such thin walls, occasionally the micro cracks in the plastic will extend from one cavity to the other, resulting in voltage breakdowns between adjacent contacts when sufficiently high current passes through the connector. In addition, if the connector is subjected to moisture, water may become loaded into the cracks between the contact cavities, which further leads to voltage breakdowns between the cavities. The foregoing problem may occur when using other plastic materials as connector insulators.
We have attempted to overcome the problem of stress cracks in the walls of the contact cavities by impregnating the cavities with an epoxy and other resin to seal the cracks but without success. Accordingly, the purpose of the present invention is to provide some means for sealing micro cracks which may exist in a connector insulator in order to prevent, or at least minimize, the possibility of voltage breakdown between adjacent contact cavities.